Sidebar by Ed Quillen
Water – October 2003 – Colorado Central Magazine
There are three major and growing Front Range cities which use water from the Arkansas River: Pueblo, population 102,121 in 2000; Colorado Springs, 380,890; and Aurora, 275,393. How much do they threaten flows in the river?
As far as Chaffee County and the Upper Arkansas Valley are concerned, Pueblo is an ally, not a threat, at least with its current delivery system. That’s because the river is Pueblo’s delivery system.
When Pueblo imports Western Slope water (as it does through ditches around Tennessee Pass, or various tunnels), or just uses native flows, the water runs down the river to Pueblo Reservoir. That’s where a new pipeline leads to the city’s treatment plant.
“The more water we have, the more you have in the river up there,” explained Paul Fanning, director of public affairs for the city’s water department.
Fanning said that Pueblo increases the river’s flow by about 12,000 acre-feet each year, thanks to its imports from the Western Slope. About 1,200 of that is from the Fryingpan-Arkansas Project, and the rest comes from Pueblo’s ditches and tunnels.
COLORADO SPRINGS has been a threat in the past, and may become one again in the future, but its current plans would not affect flows here.
About 20 years ago, the city began buying farms and associated water rights downstream from Pueblo. In total, the city purchased about 28,000 annual acre-feet (AAF), according to Steve Berry, spokesman for the utility department.
Then the city had to find a way to store and deliver the water, which led to a proposal in the early 1990s for a dam at Elephant Rock, a few miles north of Buena Vista. From that reservoir, the city would have pumped water over the Mosquito Range — either with a new facility, or an expansion of the Otero Pump Station — to the city.
Elephant Rock was strongly opposed in Chaffee County, since it could have substantially reduced downstream river flow through Buena Vista and Salida.
Since then, Colorado Springs has taken a new approach called the Southern Supply System. In essence, it would pump water through a big pipe from Pueblo Reservoir up to Colorado Springs. The City of Pueblo has some problems with this, since it could reduce flows through a river park it is developing — but up here, the water would still flow for rafting, fishing, and scenery.
So if Colorado Springs gets its Southern Supply System, it isn’t a threat to the Arkansas’ flow, and won’t be for some time to come.
Berry said that 99% of the water that Colorado Springs pumps out at Otero is imported from the Western Slope, and thus was never part of the river’s natural flow.
As for Elephant Rock, “it’s still a possibility we might pursue someday, but that’s a long way off. Our current priority is the Southern Supply System.”
Pueblo will likely never be a threat to the flows in the Arkansas, and Colorado Springs won’t be one for several decades, if ever.
No matter where Colorado Springs goes for additional water, pumping will be involved, since it sits 6,000 feet above sea level on a plateau that is naturally watered only by tiny Fountain Creek.
The costs for pumping water up 1,200 feet at Otero, or up 1,200 feet from Pueblo Reservoir, are going to be about the same. That discussion thus moves from economics and engineering to politics, and local river outfitters were able to mobilize opposition to Elephant Rock in 1990, and would presumably be able to do so again.
THEN THERE’S AURORA, which sits just east of Denver. Like Colorado Springs, it also bought farmland and water rights on the Arkansas east of Pueblo. Unlike Colorado Springs, Aurora has only one place to take water from the Arkansas River — the Otero Pump Station, which it jointly operates with Colorado Springs.
Peter Binney, Aurora director of utilities, explained that Aurora imports about 15,000 AAF of Western Slope water into the Arkansas. The city owns 5% of the Twin Lakes Tunnel water shares, for about 2,000 AAF. Aurora and Pueblo each own half of the water conveyed through the Busk-Ivanhoe Tunnel (the old Colorado Midland Railroad tunnel) west of Leadville, so Aurora gets about 2,000 AAF there. Aurora partners with Colorado Springs on the Homestake Project above Leadville, for another 10,000 to 12,000 AAF.
As for native flows on the upper river, Aurora owns about 200 AAF from Lake Creek, and has purchased three ranches in Lake County for their water (about 1,100 AAF).
Below Pueblo, Aurora owns 8,500 AAF of Rocky Ford Ditch water with an 1874 decree, and it is in the process of buying another 5,100 AAF. It also owns 7,900 AAF from the Colorado Canal with an 1890 priority date, and it is working to lease about 10,000 AAF from the High Line Canal, with priority dates ranging from 1861 to 1890.
This is water that once flowed down the Arkansas in Central Colorado to the farms east of Pueblo. When Aurora acquires the water, the city gets a “change in point of diversion” to take the water upstream at the Otero Pump Station, where it can flow into South Park and the city’s Spinney Mountain Reservoir.
That’s the water that Chaffee County Commissioners are concerned about — water which once flowed through the county, but is now diverted upstream from most of the county and from America’s most popular stretches of whitewater rafting.
How big a future threat is this? The Otero Pump Station has a capacity of 118 million gallons per day (MGD). In essence, Colorado Springs uses its 60% share to pump only imported water, so it doesn’t count when we’re talking about protecting native flows through Chaffee County.
Aurora’s share of that capacity is 50.8 MGD, which works out to about 57,000 AAF. Subtract 15,000 AAF of imported water, and that leaves 42,000 AAF. From that, we can subtract the native flows that it currently pumps, about 17,700 AAF, leaving 24,300 AAF of capacity — water that Aurora could remove from the Arkansas in the future.
If you removed 24,300 AAF from the upper Arkansas at a constant rate, you’d be pumping about 33.3 cubic feet per second (cfs or cusecs). Flows in the Arkansas through Salida typically range from 225 cfs in February to 2,000 in June.
Thus if Aurora took all the native flow that was physically possible to take, the river at its lowest would still have 85% of its current flow. That may not be desirable, but it’s not a disaster, either.
Further, Aurora is a party to the current voluntary flow management on the river, which provides for at least 700 cfs during the summer floating season, and Binney said the city plans to continue that relationship.
Add all of that up, and Aurora is not in a position to dry up the upper Arkansas, or even come close. It doesn’t have the machinery to remove that much water, even if it could acquire the water rights. The capacity of the Otero Pump Station is the limit on what Aurora can take.
To protect the river’s flows in the long term, however, Chaffee County needs to keep the Otero Pump Station from growing, since that’s the place were water can be removed from the river.
While it might be impossible to legislate against expanding the facility (the Colorado constitution says the right to divert shall never be denied), the county might be able to use its revised 1041 regulations, adopted earlier this year, to attach conditions to an expansion that would make it too expensive to pursue.
There is also the possibility of obtaining instream flow rights, perhaps for Salida’s new river park. These would affect future changes in point of diversion, but they wouldn’t affect Aurora’s current plans since, as Binney pointed out, the applications for changes have already been filed, and would thus be senior to any instream flow right Salida might claim in the future.
Thus Chaffee County’s options are limited — but so is Aurora’s capacity to take water from the Arkansas. — Bob Engle and Ed Quillen
